Description The ministers of the cabinet were quite upset by the message from the Chief of Security stating that they would all have to change the four-digit room numbers on their offices. — It is a matter of security to change such things every now…

Prime Path The ministers of the cabinet were quite upset by the message from the Chief of Security stating that they would all have to change the four-digit room numbers on their offices. — It is a matter of security to change such things every now a…

Prime Path POJ - 3126 题意: 给出两个四位素数 a , b.然后从a开始,每次可以改变四位中的一位数字,变成 c,c 可以接着变,直到变成b为止.要求 c 必须是素数.求变换次数的最小值.(a,b,c都是四位数字,输入时没有前导零) 分析: 每次改变可以获得一个四位数c,然后如果c是素数并且之前没有出现过,那么我们把它放入队列即可. int f[10001]; int v[10001]; void init()//素数筛 { memset(f,0,sizeof f); fo…

Description The ministers of the cabinet were quite upset by the message from the Chief of Security stating that they would all have to change the four-digit room numbers on their offices. — It is a matter of security to change such things every now…

题目: http://poj.org/problem?id=3126 困得不行了,没想到敲完一遍直接就A了,16ms,debug环节都没进行.人品啊. #include <stdio.h> #include <string.h> #include <queue> using namespace std; ]; ]; int s, t; void prime_init() { memset(prime, , sizeof(prime)); prime[] = ; ; i…

题目地址:http://poj.org/problem?id=3126 Input One line with a positive number: the number of test cases (at most 100). Then for each test case, one line with two numbers separated by a blank. Both numbers are four-digit primes (without leading zeros). Ou…

[题目链接]click here~~ [题目大意]给你n,m各自是素数,求由n到m变化的步骤数,规定每一步仅仅能改变个十百千一位的数,且变化得到的每个数也为素数 [解题思路]和poj 3278类似.bfs+queue,分别枚举个十百千的每一位就能够了,只是注意个位仅仅能为奇数,且千位从1開始 代码: #ifndef _GLIBCXX_NO_ASSERT #include <cassert> #endif #include <cctype> #include <cerrno&g…

<题目链接> 题目大意: 给你两个四位数,它们均为素数,以第一个四位数作为起点,每次能够变换该四位数的任意一位,变换后的四位数也必须是素数,问你是否能够通过变换使得第一个四位数变成第二个四位数. 解题分析: 先打一张素数表,然后进行BFS搜索,对于每次搜索的当前数,枚举某一位与它不同的所有数,判断它是否符合条件,如果符合,就将它加入队列,继续搜索. #include<stdio.h> #include<string.h> #include<iostream>…

思路:宽度优先搜索(BFS算法) #include<iostream> #include<stdio.h> #include<cmath> #include<cstring> using namespace std; int a,b; struct node{ int num; int step; }; node que[10000];//默认初始化为0 int visit[10000];//默认初始化为0 int prime(int d){ if(d<…

POJ 3126 Prime Path(素数路径) Time Limit: 1000MS    Memory Limit: 65536K Description - 题目描述 The ministers of the cabinet were quite upset by the message from the Chief of Security stating that they would all have to change the four-digit room numbers on…